多道电子束扫描搭接率对40Cr钢组织与性能的影响

Effect of multi-pass electron beam scanning overlap rate on microstructure and properties of 40Cr steel

对40Cr钢在不同搭接率下进行多道电子束扫描表面改性处理,并对其显微组织和力学性能进行了研究。结果表明,经多道电子束扫描表面改性处理,40Cr钢表面搭接区因回火生成回火马氏体及回火索氏体;重熔层中马氏体组织随着搭接率的增大而变得粗大。搭接率为0%时,电子束处理区域的平均显微硬度为627.4 HV0.2;搭接率增大,搭接区域表面显微硬度下降。当搭接率为25%时,试样表面光滑平整,粗糙度为1.083μm;表面粗糙度随着搭接率的增大先减小后增大;40Cr钢耐磨性较电子束扫描处理前有明显改善。耐磨性随着搭接率的增大先增大后减小。

Multi-pass electron beam scanning surface modification was carried out on 40 Cr steel with different overlap rates,and microstructure and properties was studied.The results show that after multi-pass electron beam scanning surface modification,tempered martensite and tempered sorbite are formed in the overlapping area of 40 Cr steel due to tempering,and the martensite structure in the remelted layer becomes coarsen with the increase of overlap rate.When the overlap rate is 0%,the average microhardness of the electron beam treatment area is 627.4 HV0.2,with the increase of overlap rate,the microhardness of overlap area decreases.When the overlap rate is 25%,the surface of the specimen is smooth and flat,and the roughness is 1.083μm.The surface roughness first decreases and then increases with the increase of overlap rate.In addition,the wear resistance of the 40 Cr steel is significantly improved compared with that before electron beam treatment.The wear resistance first increases and then decreases with the increase of overlap rate.